| 摘要 |
PROBLEM TO BE SOLVED: To provide a hybrid delay lock loop where excellent tracking accuracy by a 1st delay lock loop is compatible with wideness of a synchronization maintenance range of a 2nd delay lock loop. SOLUTION: Multipliers 9a, 9b, 9c of a delay lock group 1 used for a synchronization tracing circuit in a reception station of the mobile communication system multiply respectively a reception signal (2) with an Early PN code 4a, a 1Δ rate PN code 4b and a 2 ΔPN code 4c whose phases are delayed more than that of the Early PN code 4a to conduct reverse spread. Band pass filters 7a, 7b, 7c extract a modulation wave using a transmission frequency for a center frequency, based on outputs of the multipliers 9a, 9b, 9c. Envelope detectors 8a, 8b, 8c measure power of the extracted modulation wave to obtain a plurality of correlation output signals. A selection circuit 5 selects a specific early or late correlation output signal among the plurality of correlation output signals. |
